Some comments on the mechanism of orientation of organic solutes in stretched polyethylene

Comparisons of Photo-Fries Rearrangements of 4-Dodecylphenyl Phenylacetate and Two Structurally Related Esters in Hexane and Polyethylene Cages. How Important Are Anchoring Chains?†

“…Furthermore, aryl esters reside both within the amorphous part and at interfacial sites (along the interfaces between crystallites and amorphous regions) of partkdlly crystalline PE films; they do not enter the crystalline portions (30)(31)(32)(33). The distribution of guests between these two site types varies with the specific PE film, but the interfacial concentration usually increases with increasing degree of crystallinity or after a film is stretched (30)(31)(32)(33)37). The distribution is important because molecules in the two site types can behave differently.…”

“…Previously, we have conducted photo-Fries reactions of PPA and other aromatic esters in several types of polyethylene (PE) films (15)(16)(17)(18)(19)(20). Because the van der Waals volumes of the esters are significantly larger than the mean hole free volumes within the PE (29), the fates of the radical pairs appear to depend upon the specific type of cavity in which the aromatic ester resides at the moment of its electronic excitation-both amorphous and interfacial sites are possible in partially crystalline PE hosts (vide infra) (30)(31)(32)(33). Both free volume and templating (i.e.…”

Chiroptical Properties of Terthiophene Chromophores Dispersed in Oriented and Unoriented Polyethylene Films

“…The UV-Vis dichroic ratios (R), calculated as previously described from polarized UV-Vis absorption spectra ( Figure 6), [11] are collected in Table 1 for different samples as a function of the drawing ratio. e Oriented UHMWPEII and UHMWPEIIr provided similar dichroic ratio R values, with slightly higher values for the former.…”

Dielectric relaxation of polar aromatics in unoriented and oriented linear low-density polyethylene

“…The sites of guest molecules are within the amorphous phase between the crystal lamellae. 7 The probe molecules 2BFL and 9BFL exhibit rodlike shapes, but differ in the direction of their dipole moment, being nearly parallel or perpendicular to the long axis of the molecules, respectively. The rather spherical guest (1D4M) is likely to widen the host's molecular structure and may cause a plasticizing effect.…”